1. Field of the Invention
This invention relates to a method of preparing lactone acid compounds in excellent yields, and more particularly this invention relates to the preparation of lactone acid esters and their use in fluid systems or as intermediates.
2. Description of the Prior Art
Copending U.S. application Ser. No. 212,626, filed on Dec. 27, 1971, now abandoned discloses the preparation of hydroxyamide soaps and lactam acetic acid amides from lactone acids. These lactone acids are the products of acid hydrolysis of alkenylsuccinic anhydrides. The preparation takes over 15 hours and achieves only about 40 to 50 percent conversion of anhydride to lactone acid, and requires a second 15-hour or more conversion or recycled unreacted anhydride. For example, a two-step 34-hour reaction cycle may yield no more than about 75% lactone acid based on initial anhydride.
U.S. Pat. Nos. 3,200,075 and 3,261,782 describe the preparation of a methyl lactone ester by reacting dimethyl bromosuccinate and an olefin in the presence of a peroxide. Cyclization to the lactone occurs through the removal of a methyl group.